Mesh network of intelligent devices communicating via powerline and radio frequency

Abstract

Low-cost intelligent control and communication devices are arranged to communicate with one another over one or more shared physical media, such as a powerline or a radio frequency band. No network controller is needed, because any device can act as a master, slave, or repeater. Adding more devices makes the system more robust, by virtue of a simple protocol for communication retransmissions and retries.

1. A communication module for use in a system including a plurality of said communication modules, said communication module comprising:
 circuitry for storing a number, referred to as a module address, designating an address for said communication module; 
 circuitry for sending and receiving messages over at least one communications medium; 
 circuitry and software for generating messages and for receiving and deciphering messages; 
 each of said messages comprising a first number field, referred to as an originator address, designating the module address of the module originating the message, a second number field, referred to as a recipient address, designating the module address of an intended recipient module, a third number field, referred to as message flags, designating the type of message, a fourth number field, referred to as a maximum retransmission count, designating the maximum number of retransmissions for the message, a fifth number field, referred to as a current retransmission count, designating how many times the message has already been retransmitted, a sixth number field, referred to as a command field, designating an action, and a seventh number field, referred to as a message validator, designating a message integrity validation; 
 circuitry and software for determining if a received message has reached all of its intended recipients by inspecting said message flags and by comparing said recipient address to said module address; 
 circuitry and software for determining if a received message has already been retransmitted a maximum number of times for that message by comparing said maximum retransmission count and said current retransmission count; and 
 
     circuitry and software for retransmitting a received message with said current retransmission count altered by one, but only if said received message has not reached all of its intended recipients and has not already been retransmitted the maximum number of times. 
   
   
     2. The communication module of  claim 1  being constructed and arranged to send and receive messages over the mains powerline. 
   
   
     3. The communication module of  claim 2  wherein said messages each comprise a plurality of signal packets, wherein each of said signal packets is synchronized with the zero crossing of an alternating current on the mains powerline. 
   
   
     4. The communication module of  claim 3  wherein the number of said signal packets comprised in each of said messages is determined by one bit in said message flags. 
   
   
     5. The communication module of  claim 4  wherein the number of said signal packets comprised in each of said messages is five if said bit is zero and eleven if said bit is one. 
   
   
     6. The communication module of  claim 4  wherein each of said messages comprises an arbitrary data field if said bit is one. 
   
   
     7. The communication module of  claim 6  wherein said arbitrary data field comprises fourteen bytes. 
   
   
     8. The communication module of  claim 3  comprising circuitry and software for waiting after sending or receiving one of said messages for at least an additional one of said zero crossings to occur before sending another message. 
   
   
     9. The communication module of  claim 3  wherein the number of said zero crossing periods for sending said messages is fixed for a given length message and messages are only sent beginning at a time period, referred to as a message time slot, comprising an integer multiple of said fixed number of said zero crossing periods. 
   
   
     10. The communication module of  claim 9  comprising circuitry and software for sending retransmitted messages at the same time as other of said communication modules are sending identical messages. 
   
   
     11. The communication module of  claim 9  comprising circuitry and software for sending a first retransmitted message during the first of said message time slots after the original message is sent, and subsequent retransmitted messages during subsequent ones of said message time slots. 
   
   
     12. The communication module of  claim 9  comprising circuitry and software for originating and sending new messages only after the number of said message time slots elapsing after a previous message is sent by an originating communication module is equal to a number, referred to as a new message time slot delay, that is one plus said maximum retransmission count. 
   
   
     13. The communication module of  claim 12  wherein, if the intended recipient module of said previous message can send an acknowledgement message to the originator of said previous message, said new message time slot delay is increased by one plus said maximum retransmission count. 
   
   
     14. The communication module of  claim 3  comprising circuitry and software for detecting if other communication modules are sending messages and, if other messages are being sent, waiting for an integer number of said zero crossings before originating a new message. 
   
   
     15. The communication module of  claim 3  comprising circuitry and software for retrying to send a message a fixed number of times if an acknowledgement message is not received from the intended recipient of said message. 
   
   
     16. The communication module of  claim 15  comprising circuitry and software for incrementing, each time said message is retried, said maximum retransmission count, but not incrementing said maximum retransmission count past a maximum value allowed for retransmitting messages. 
   
   
     17. The communication module of  claim 3  wherein said signal packets begin with a bit pattern for synchronizing receiving circuitry, and said bit pattern is longer for the first of said plurality of signal packets. 
   
   
     18. The communication module of  claim 17  wherein said bit pattern comprises eight bits for the first of said signal packets and two bits for the remainder of said signal packets. 
   
   
     19. The communication module of  claim 3  wherein said signal packets begin before and end after said zero crossing of said alternating current. 
   
   
     20. The communication module of  claim 19  wherein said signal packets begin 800 microseconds before and end 1023 microseconds after said zero crossings of said alternating current. 
   
   
     21. The communication module of  claim 3  comprising circuitry and software for sending and receiving signal packets using binary phase-shift keying of a carrier signal applied to the mains powerline. 
   
   
     22. The communication module of  claim 21  wherein said carrier signal has a frequency of 131.65 kilohertz. 
   
   
     23. The communication module of  claim 21  comprising circuitry and software for gradually shifting the phase of said carrier signal by inserting one and one-half cycles of signal at one and one-half times the frequency of said carrier signal. 
   
   
     24. The communication module of  claim 3  comprising circuitry for sending and receiving X10 messages conforming to the X10 communications protocol. 
   
   
     25. The communication module of  claim 24  comprising circuitry and software for receiving said X10 messages if another binary phase-shift keyed signal is not received within 450 microseconds after the zero crossing of an alternating current on the mains powerline. 
   
   
     26. The communication module of  claim 24  comprising circuitry and software for continuing to receive one of said X10 messages until said X10 message is completed. 
   
   
     27. The communication module of  claim 1  including an RE transceiver device for sending and receiving messages on a radio frequency. 
   
   
     28. The communication module of  claim 27  wherein said radio frequency is an open, non-restricted radio frequency. 
   
   
     29. The communication module of  claim 27  comprising circuitry and software for sending retransmitted messages via said radio frequency at the same time as other of said communication modules are sending identical messages via said radio frequency. 
   
   
     30. The communication module of  claim 1  being constructed and arranged to send and receive messages over the mains powerline and also over a radio frequency. 
   
   
     31. The communication module of  claim 30  comprising circuitry and software for retransmitting using said radio frequency a message received via the mains powerline, and for retransmitting using the mains powerline a message received via said radio frequency. 
   
   
     32. The plurality of communication modules of  claim 30 , with at least one of said communications modules connected to a different phase of the mains powerline, such that messages propagating on one phase of the mains powerline are propagated on another phase of the mains powerline after being relayed using said radio frequency. 
   
   
     33. The communication module of  claim 30  comprising circuitry and software for sending and receiving messages via said radio frequency beginning at the next zero-crossing of the mains powerline following reception or transmission of messages via the mains powerline. 
   
   
     34. The communication module of  claim 33  wherein said messages sent and received via said radio frequency are the same messages sent and received via the mains powerline. 
   
   
     35. The communication module of  claim 1  wherein said maximum retransmission count varies from zero to a small integer. 
   
   
     36. The communication module of  claim 35  wherein said small integer is three. 
   
   
     37. The communication module of  claim 1  comprising circuitry and software which, upon receiving one of said messages with said recipient address matching said module address, sends an acknowledgement message to the module originating the message by interchanging said recipient address and said originator address. 
   
   
     38. The communication module of  claim 1  comprising circuitry and software for determining that a received message is correct and not corrupted by using said message validator as a cyclic redundancy check. 
   
   
     39. The communication module of  claim 38  comprising circuitry and software that sends a non-acknowledgement message to the module originating the message if the message is determined to be corrupted. 
   
   
     40. The communication module of  claim 1  comprising circuitry and software for maintaining a database containing group membership associations between a group number and a plurality of module addresses of other communication modules. 
   
   
     41. The communication module of  claim 40  comprising circuitry and software for sending a message referred to as a group broadcast message to a plurality of communication modules by including said group number in said recipient address, setting a first bit in said message flags to a value indicating that said message is a group message, and setting a second bit in said message flags to a value indicating that all modules associated with said group number are intended message recipients. 
   
   
     42. The communication module of  claim 41  comprising circuitry and software for following said group broadcast message with a message referred to as a group follow-up message to each one of said plurality of communication modules, with said recipient address matching one of said module addresses associated with said group number in said database of said communication module, said command field containing said group number, said first bit in said message flags set to a value indicating that said message is a group message, and said second bit in said message flags set to a value indicating that only one module associated with said group number is the intended message recipient. 
   
   
     43. The communication module of  claim 40  comprising circuitry and software for receiving a message referred to as a group broadcast message with said group number in said recipient address, a first bit in said message flags set to a value indicating that said message is a group message, and a second bit in said message flags set to a value indicating that all modules associated with said group number are intended message recipients, wherein said communication module only processes said message if said database contains an association between said group number and the address of the communication module originating said message. 
   
   
     44. The communication module of  claim 43  comprising circuitry and software for receiving a message referred to as a group follow-up message with said recipient address matching said module address, said command field containing said group number, a first bit in said message flags set to a value indicating that said message is a group message, and a second bit in said message flags set to a value indicating that only one module associated with said group number is the intended message recipient, wherein said communication module only processes said follow-up message if it did not previously process said group broadcast message. 
   
   
     45. The communication module of  claim 1  comprising serial communications interface circuitry and software for communicating with another network using a different signaling protocol. 
   
   
     46. The communication module of  claim 1  comprising serial communications interface circuitry and software for communicating with external digital equipment. 
   
   
     47. The communication module of  claim 46  wherein said serial communications interface circuitry and software comprises a Universal Serial Bus link. 
   
   
     48. The communication module of  claim 46  wherein said serial communications interface circuitry and software comprises an RS232 link. 
   
   
     49. The communication module of  claim 46  wherein said serial communications interface circuitry and software comprises an Ethernet link. 
   
   
     50. The communication module of  claim 46  wherein said serial communications interface circuitry and software comprises an Internet Protocol connection. 
   
   
     51. The communication module of  claim 1  comprising control circuitry for operating a device associated with said communication module. 
   
   
     52. The communication module of  claim 51  wherein said associated device comprises circuitry for delivering varying amounts of current to a load. 
   
   
     53. The communication module of  claim 51  wherein said associated device comprises circuitry for sensing the amount of current drawn by a load. 
   
   
     54. The communication module of  claim 51  wherein said associated device comprises a plurality of push button switches for initiating a plurality of command functions. 
   
   
     55. The communication module of  claim 51  wherein said associated device comprises a graphical display with a plurality of push button switches for initiating a plurality of command functions. 
   
   
     56. The communication module of  claim 51  wherein said associated device comprises a graphical display with a touch screen. 
   
   
     57. The communication module of  claim 51  wherein said associated device comprises a sensor for determining the state of the environment. 
   
   
     58. The communication module of  claim 51  wherein said associated device comprises voice response circuitry and software. 
   
   
     59. The communication module of  claim 51  wherein said associated device comprises voice recognition circuitry and software. 
   
   
     60. The communication module of  claim 51  wherein said associated device comprises image capture and processing circuitry and software. 
   
   
     61. The communication module of  claim 51  comprising a housing with a bottom member attached to one of a mounting for resting on a desktop, or a mounting for attaching to a wall. 
   
   
     62. The communication module of  claim 51  comprising at least one white light-emitting diode with an interchangeable colored filter for altering the viewed color of said light-emitting diode. 
   
   
     63. A method for sending and receiving messages containing digital information among communicating modules, said method comprising the steps of:
 providing each module with an address, referred to as a module address; 
 providing each message with a first number field, referred to as an originator address, designating the module address of a module originating said message; 
 providing each message with a second number field, referred to as a recipient address, designating the module address of an intended recipient module; 
 providing each message with a third number field, referred to as message flags, designating the type of message; 
 providing each message with a fourth number field, referred to as a maximum retransmission count, designating the maximum number of retransmissions for said message; 
 providing each message with a fifth number field, referred to as a current retransmission count, designating how many times said message has already been retransmitted; 
 providing each message with a sixth number field, referred to as a command field, designating an action; 
 providing each message with a seventh number field, referred to as a message validator, designating a message integrity validation; 
 determining if a received message has reached all of its intended recipients by inspecting said message flags and by comparing said recipient address to said module address; 
 determining if a received message has already been retransmitted a maximum number of times for that message by comparing said maximum retransmission count and said current retransmission count; and 
 retransmitting a received message with said current retransmission count altered by one, but only if said received message has not reached all of its intended recipients and has not already been retransmitted the maximum number of times.